Примеры использования Comparability graph на Английском языке и их переводы на Русский язык
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Every comparability graph is perfect.
Every bipartite graph is also a comparability graph.
Comparability graphs can also be characterized by a list of forbidden induced subgraphs.
The complement of any interval graph is a comparability graph.
He observes that every comparability graph is complete, is bipartite, or has a skew partition.
Interval graphs are exactly the graphs that are chordal and that have comparability graph complements.
As Seymour(2006) observes, every comparability graph that is neither complete nor bipartite has a skew partition.
Trivially perfect graphs have several other equivalent characterizations:They are the comparability graphs of order-theoretic trees.
Thus, a clique in a comparability graph corresponds to a chain, and an independent set in a comparability graph corresponds to an antichain.
Wolk(1962) and Wolk(1965) proved this for comparability graphs of rooted forests.
Then the comparability graph of T is trivially perfect, and every trivially perfect graph can be formed in this way.
A graph G is a permutation graph if and only if both G and its complement G¯{\displaystyle{\overline{G}}}are comparability graphs.
Every comparability graph is perfect: this is essentially just Mirsky's theorem, restated in graph-theoretic terms Berge& Chvátal 1984.
Perfect graphs include many important graphs classes including bipartite graphs, chordal graphs, and comparability graphs.
Comparability graphs formed from partially ordered sets by connecting pairs of elements by an edge whenever they are related in the partial order.
Trivially perfect graphs are also known as comparability graphs of trees, arborescent comparability graphs, and quasi-threshold graphs. .
Comparability graphs are also perfectly orderable, with a perfect ordering being given by a topological ordering of a transitive orientation of the graph. .
A graph G is a permutation graph if andonly if it is the comparability graph of a partially ordered set that has order dimension at most two.
The split comparability graphs, and therefore also the split interval graphs, can be characterized in terms of a set of three forbidden induced subgraphs.
Permutation graphs are a special case of circle graphs, comparability graphs, the complements of comparability graphs, and trapezoid graphs. .
A comparability graph is an undirected graph formed from a partial order by creating a vertex per element of the order, and an edge connecting any two comparable elements.
A poset is graded if and only if every connected component of its comparability graph is graded,so further characterizations will suppose this comparability graph to be connected.
The comparability graph of a partial order is the undirected graph with a vertex for each element and an undirected edge for each pair of distinct elements x, y with either x≤ y or y≤ x.
In some classes of graphs, it has been proven that the pathwidth and treewidth are always equal to each other: this is true for cographs, permutation graphs, the complements of comparability graphs, and the comparability graphs of interval orders.
Any induced subgraph of a comparability graph is itself a comparability graph, formed from the restriction of the partial order to a subset of its elements.
However, the algorithm for doing so will assign orientations to the edges of any graph, so to complete the task of testing whether a graph is a comparability graph, one must test whether the resulting orientation is transitive, a problem provably equivalent in complexity to matrix multiplication.
Alternatively, a comparability graph is a graph such that, for every generalized cycle of odd length, one can find an edge(x, y) connecting two vertices that are at distance two in the cycle.
If a graph family F is closed under the operation of taking induced subgraphs, then every graph in F is also locally F. For instance, every chordal graph is locally chordal;every perfect graph is locally perfect; every comparability graph is locally comparable.
Since trapezoid graphs are a subset of co-comparability graphs, if G{\displaystyle{G}} is a trapezoid graph, its complement G′{\displaystyle{G'}}must be a comparability graph.
Because comparability graphs are perfect, many problems that are hard on more general classes of graphs, including graph coloring and the independent set problem, can be computed in polynomial time for comparability graphs. .